Internal combustion engine and method for operating an internal combustion engine

Abstract

An engine controller, for an internal combustion engine, is configured to: control at least one actuator to provide an air-fuel mixture with a lambda value higher than 3 to a main combustion chamber via at least one intake valve, wherein the at least one actuator is arranged upstream of at least one intake port or which is arranged in the intake port; control at least one fuel supply system to provide fuel directly to the main combustion chamber and/or a pre-combustion chamber of a piston-cylinder unit such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than the lambda value of the air-fuel mixture provided to the main combustion chamber via the at least one intake valve.

The invention claimed is: 
     
         1 . An internal combustion engine, comprising:
 at least one piston-cylinder unit in which an air-fuel mixture is combustible,   at least one intake port fluidically connected to the at least one piston-cylinder unit of the internal combustion engine, the at least one intake port being fluidically separable from the at least one piston-cylinder unit via at least one intake valve,   at least one exhaust port fluidically connected to the at least one piston-cylinder unit of the internal combustion engine, the at least one exhaust port being fluidically separable from the at least one piston-cylinder unit via at least one exhaust valve,   a fuel supply line fluidically connected to at least one fuel supply system, the at least one fuel supply system being configured to supply fuel, comprising hydrogen, directly into a main combustion chamber and/or a pre-combustion chamber of the at least one piston cylinder unit, and   an engine controller configured to control operation of the internal combustion engine, wherein the engine controller is configured to:
 control at least one actuator to provide an air-fuel mixture with a lambda value higher than a threshold lambda value to the main combustion chamber via the at least one intake valve at a first crank angle before top dead center (TDC) of a piston of the piston-cylinder unit during a compression stroke, wherein the at least one actuator is arranged upstream of the at least one intake port or which is arranged in the intake port; 
 control the at least one fuel supply system to provide the fuel comprising hydrogen directly to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit at a second crank angle after the first crank angle before TDC, such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than the lambda value of the air-fuel mixture provided to the main combustion chamber via the at least one intake valve. 
   
     
     
         2 . The internal combustion engine according to  claim 1 , wherein the threshold lambda value is 3, and wherein the engine controller is configured to control the at least one fuel supply system to provide the fuel to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than 3.5 and higher than 1.5 in the case when the air-fuel mixture provided to the piston-cylinder unit via the at least one intake valve is 3.5 or more. 
     
     
         3 . The internal combustion engine according to  claim 1 , wherein the threshold lambda value is 3, and wherein the engine controller is configured to control the at least one fuel supply system to provide the fuel to the piston-cylinder unit such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than 2.7 and higher than 2.1. 
     
     
         4 . The internal combustion engine according to  claim 1 , comprising:
 an exhaust gas recirculation system (EGR) comprising an exhaust gas recirculation valve, and   wherein the engine controller is configured to:
 control the exhaust gas recirculation valve to admix up to 50% of an exhaust gas to the air-fuel mixture provided to the main combustion chamber via the at least one intake valve, wherein the threshold lambda value is 1.3. 
   
     
     
         5 . The internal combustion engine according to  claim 4 , wherein the engine controller is configured to control the at least one fuel supply system to provide the fuel to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the piston-cylinder unit is lower than 1.1 and higher than 0.9. 
     
     
         6 . The internal combustion engine according to  claim 1 , wherein the fuel supply system comprises a passive and/or active gas valve and/or at least one direct injection valve configured to directly supply fuel to the main combustion chamber and/or the pre-combustion chamber. 
     
     
         7 . The internal combustion engine according to  claim 1 , wherein the at least one actuator is a fuel supply valve arranged upstream of the intake port, wherein the fuel supply valve is fluidically connected to a mixing device, and the mixing device is configured to mix air with fuel from a fuel source provided via the fuel supply valve. 
     
     
         8 . The internal combustion engine according to  claim 7 , wherein the mixing device is arranged upstream or downstream of a compressor of a turbo charger. 
     
     
         9 . The internal combustion engine according to  claim 1 , wherein the at least one actuator is a port injection valve being arranged in the at least one intake port. 
     
     
         10 . The system according to  claim 1 , wherein the engine controller is configured to provide the air-fuel mixture via the at least one intake valve during an opening period of the at least one intake valve, and the engine controller is configured to provide the fuel with the at least one fuel supply system during an injection period of the at least one fuel supply system, wherein the injection period of the at least one fuel supply system is during a crank angle between 20° before closing of the at least one exhaust valve and 40° before the piston of the at least one piston-cylinder unit reaches the TDC during the compression stroke. 
     
     
         11 . The system according to  claim 1 , wherein the second crank angle is between a closing of the at least one exhaust valve and 60° before the piston of the at least one piston-cylinder unit reaches the TDC during the compression stroke. 
     
     
         12 . The system according to  claim 1 , wherein at essentially 100% possible mechanical power output of the internal combustion engine the at least one fuel supply system is configured to provide the fuel to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit with an energy amount of maximum 60% of the total energy amount provided to the piston-cylinder unit. 
     
     
         13 . The system according to  claim 1 , wherein up to 33% of the maximal possible mechanical power output of the internal combustion engine 100% of the total energy amount is provided to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit via the fuel supply system and/or between 33% and 66% of the maximal possible mechanical power output of the internal combustion engine up to 60% of the total energy amount is provided to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit via the fuel supply system and/or between 66% and 100% of the maximal possible mechanical power output of the internal combustion engine up to 30% of the total energy amount is provided to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit via the fuel supply system. 
     
     
         14 . The internal combustion engine according to  claim 1 , wherein the air-fuel mixture is a mixture of air and fuel comprising hydrogen. 
     
     
         15 . A method for operating the internal combustion engine according to  claim 1 , comprising the following steps:
 provide the air-fuel mixture with the lambda value higher than 3 to the main combustion chamber of the at least one piston-cylinder unit via the at least one intake valve, and   provide the fuel, comprising the hydrogen, directly to the main combustion chamber and/or the pre-combustion chamber of the piston-cylinder unit via the at least one fuel supply system such that at the time of ignition of the air-fuel mixture the lambda value of the air-fuel mixture in the main combustion chamber and/or the pre-combustion chamber is lower than the lambda value of the air-fuel mixture provided to the main combustion chamber via the at least one intake valve.   
     
     
         16 . A system, comprising:
 an engine controller configured to control operation of an internal combustion engine, wherein the engine controller is configured to:
 control at least one actuator to provide an air-fuel mixture with a lambda value higher than a threshold lambda value to a main combustion chamber via at least one intake valve at a first crank angle before top dead center (TDC) of a piston of the piston-cylinder unit during a compression stroke, wherein the at least one actuator is arranged upstream of at least one intake port or which is arranged in the intake port; and 
 control at least one fuel supply system to provide a fuel comprising hydrogen directly to the main combustion chamber and/or a pre-combustion chamber of a piston-cylinder unit at a second crank angle after the first crank angle before TDC, such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than the lambda value of the air-fuel mixture provided to the main combustion chamber via the at least one intake valve. 
   
     
     
         17 . The system according to  claim 16 , wherein the engine controller is configured to control the at least one actuator to provide the air-fuel mixture with the lambda value higher than the threshold lambda value to inhibit combustion, and the engine controller is configured to control the at least one fuel supply system to provide the fuel such that at the time of ignition of the air-fuel mixture the lambda value enables combustion. 
     
     
         18 . The system according to  claim 16 , wherein the second crank angle is at least at or after 20° before closing of the at least one exhaust valve, at or before 40° before the piston of the at least one piston-cylinder unit reaches the TDC during the compression stroke, or a combination thereof. 
     
     
         19 . The system according to  claim 16 , wherein the engine controller is configured to control the at least one fuel supply system to provide the fuel comprising hydrogen directly to the main combustion chamber and/or the pre-combustion chamber with an energy amount of at least up to 30%, 60%, or 100% of a total energy amount provided to the piston-cylinder unit. 
     
     
         20 . A method, comprising:
 controlling, via an engine controller, operation of an internal combustion engine, wherein controlling comprises:
 controlling at least one actuator to provide an air-fuel mixture with a lambda value higher than a threshold lambda value to a main combustion chamber via at least one intake valve at a first crank angle before top dead center (TDC) of a piston of the piston-cylinder unit during a compression stroke, wherein the at least one actuator is arranged upstream of at least one intake port or which is arranged in the intake port; and 
 controlling at least one fuel supply system to provide a fuel comprising hydrogen directly to the main combustion chamber and/or a pre-combustion chamber of a piston-cylinder unit at a second crank angle after the first crank angle before TDC, such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than the lambda value of the air-fuel mixture provided to the main combustion chamber via the at least one intake valve.